login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A249280 Repeatedly apply 'Reverse and add' to n. a(n) gives the number of steps needed to reach a sum containing each digit from 0 to 9 at least once. 1
38, 37, 35, 36, 54, 34, 45, 35, 48, 53, 52, 33, 51, 44, 32, 34, 50, 47, 43, 52, 33, 51, 44, 32, 34, 50, 47, 43, 42, 33, 51, 44, 32, 34, 50, 47, 43, 42, 31, 51, 44, 32, 34, 50, 47, 43, 42, 31, 41, 44, 32, 34, 50, 47, 43, 42, 31, 41, 33, 32, 34, 50, 47, 43, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Conjecture 1: a(n) exists for all n.

Conjecture 2: There exists an upper bound c such that a(n) < c for all n.

The conjectures seem highly likely, especially since a(n) = 0 for almost all n. A lower bound for c is a(1418993) = 73. (Checked to 10^9.) - Charles R Greathouse IV, Oct 28 2014

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Felix Fröhlich, C++ program for this sequence

PROG

(PARI) fromdigits(v, b=10)=subst(Pol(v), 'x, b) \\ needed for gp < 2.63 or so

A056964(n)=fromdigits(Vecrev(digits(n)))+n

ispan(n)=#Set(digits(n))==10

a(n)=my(k); while(!ispan(n), n=A056964(n); k++); k \\ Charles R Greathouse IV, Oct 28 2014

CROSSREFS

Cf. A056964.

Sequence in context: A033974 A143721 A070725 * A022994 A023480 A036743

Adjacent sequences:  A249277 A249278 A249279 * A249281 A249282 A249283

KEYWORD

nonn,base,easy

AUTHOR

Felix Fröhlich, Oct 26 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 15 14:04 EDT 2019. Contains 327078 sequences. (Running on oeis4.)